The present invention relates to the field of P-I-N photodetectors.
P-I-N photodetectors are fabricated by providing a top layer of heavily doped p+ semiconductor material, an intermediate layer of lightly-doped n.sup.- semiconductor material overlaying a substrate of heavily doped n+ material. The p+ and n.sup.- layers are thereafter etched to form mesas of these layers upon the substrate. The p+/n.sup.- interface is, however, exposed to air to produce leakage currents which increase over time, resulting in unsatisfactory operation or device failure, unless the interface is passivated. For a detailed description of such P-I-N photodetectors, see Pat. No. 4,477,964 and the papers listed therein.